Could not find the metadata of an IdP with entity ID 'urn:mace:incommon:xxxx.edu'" at /var/www/html/vendor/simplesamlphp/simplesamlphp/modules/saml/lib/Auth/Source/SP.php

Problem/Motivation

Trying to configure SAML authentication

Steps to reproduce

1. Install SimpleSAMLPHP 2.0.2 base application and configure as a SP; run successful tests against my campus IDP
2. Install SimpleSAMLPHP Drupal module using composer require 'drupal/simplesamlphp_auth:^3.3' on my Drupal 9.5.3
3. There are configuration instructions here https://www.drupal.org/project/simplesamlphp_auth → that I followed but I see no place to configure an IDP, as it is already configured in the base app

I have no proposed resolution but I'm wondering why https://www.drupal.org/project/simplesamlphp_auth/issues/3057851 → was closed because my problem is identical